The present relates generally to surgical devices, and more particularly to microfabricated surgical devices for use in catheter-based interventional procedures.
Biological and surgical microelectromechanical systems (MEMS), useful for their ability to be placed into and easily maneuvered within a patient""s body, are touted as the fastest growing area of micro-systems. For example, microcatheters are used in many medical applications for minimally invasive surgery. There are presently over one million surgical uses of catheters per year in the United States, representing a huge market.
As surgeons continue to adopt and perform advanced surgical procedures, the miniaturization of medical devices is taking place, allowing surgery with small external incisions and catheter-based microsurgical tools. With roots in laparoscopic surgery (entering the abdomen through the navel and small holes in the midsection), minimally invasive surgery can be performed by inserting catheters in the femoral artery at the base of a patient""s thigh, navigating the blood vessels in the patient""s body, and arriving at problem areas like the heart or brain. Once the distal tip of the catheter is precisely positioned inside the body, a microsurgical procedure like balloon angioplasty, stent placement, localized cauterization, or drug delivery can take place. With the reduced bodily reaction to microsurgery and the minimization of scar tissue, these procedures are highly preferred over more typical xe2x80x9cmacroxe2x80x9d surgeries.
In one aspect, the invention features an actuator for an interventional surgical procedure. The actuator comprises an actuator body having a distal end and a proximal end. A central expandable section is located between the distal end and the proximal end. The expandable section is operable between an unactuated condition in which the expandable section is in a furled state and an actuated condition in which the expandable section is in an unfurled state. A needle at the expandable section is movable in an approximately perpendicular direction relative to a central longitudinal axis of the actuator body from a position within the actuator body to a position outside of the actuator body when the expandable section is caused to change from the furled state to the unfurled state.
Various implementations of the invention may include one or more of the following features. The proximal end of the actuator body may be joined to an end of a catheter. The distal end of the actuator body may be joined to a tip end of the catheter. The expandable section includes an interior open area and a delivery conduit is used to supply an activating fluid to the open area to cause the expandable section to change from the furled state to the unfurled state. The expandable section may be made from a polymer. The actuator may further include a retaining ring located at the distal end and at the proximal end of the actuator body. The needle may include a tip having an insertion edge or point. The tip may include an outlet port and a fluid pathway may be used to supply a therapeutic or diagnostic agent to the outlet port. The needle is a microfabricated needle, or it is a macroneedle.
In another aspect, the invention is directed to a microfabricated surgical device for an interventional surgical procedure. The device includes a catheter having a distal end for insertion into and manipulation within a body of a vascularized organism and a proximal end for providing a user with control over the manipulation of the distal end of the catheter. An actuator is joined to the distal end of the catheter. The actuator includes an actuator body and a needle joined to an expandable section of the actuator body such that the needle is located within the actuator body when the actuator is in an unactuated condition and outside of the actuator body when the actuator is in an actuated condition. The needle is movable along a path substantially perpendicular to a central longitudinal axis of the actuator body when the actuator changes from the unactuated condition to the actuated condition. Fluid connections are provided at the distal end of the catheter and a proximal end of the actuator to supply a therapeutic or diagnostic agent to the needle, and to provide an activating fluid to the actuator to cause the actuator to change from the unactuated condition to the actuated condition.
Various implementations of the invention may include one or more of the following features. The catheter may be a therapeutic catheter. The expandable section may be in a furled state when the actuator is in the unactuated condition and in an unfurled state when the actuator is in the actuated condition. The expandable section may be made from a polymer. The device may further include a retaining ring located at opposite ends of the actuator body. The expandable section may include an interior open area to which the activating fluid is supplied to cause the expandable section to change from the furled state to the unfurled state. When the activating fluid is removed from the interior open area, the expandable section may return to the furled state.
In yet another aspect, the invention is directed to an actuator for an interventional surgical procedure comprising an actuator body having a distal end and a proximal end. A central expandable section is located between the distal end and the proximal end. The expandable section is operable between an unactuated condition in which the expandable section is in a furled state and an actuated condition in which the expandable section is in an unfurled state. A plurality of needles are located at the expandable section. The needles are movable in an approximately perpendicular direction relative to a central longitudinal axis of the actuator body from a position within the actuator body to a position outside of the actuator body, when the expandable section is caused to change from the furled state to the unfurled state.
Various implementations of the invention may include one or more of the following features. The needles may be spaced along a length of the expandable section. The plurality of needles move at the same time when the expandable section changes from the furled state to the unfurled state. At least one of the plurality of needles may move before another one of the plurality of needles when the expandable section changes from the furled state to the unfurled state. Also, when the expandable section changes from the furled state to the unfurled state, at least one of the plurality of needles may move in a direction that is different from the direction of movement of another one of the plurality of needles.
In still another aspect, the invention is directed to an actuator for an interventional surgical procedure comprising an actuator body having a distal end and a proximal end. An expandable section is located between the distal end and the proximal end. The expandable section is operable between a furled state and an unfurled state. A needle is located at the expandable section. The needle is movable from a position within the actuator body to a position outside of the actuator body, when the expandable section is caused to change from the furled state to the unfurled state.
An implementation of the invention may include a plurality of needles at the expandable section wherein when the expandable section changes from the furled state to the unfurled state, at least one of the needles moves in a direction that is different from the direction of movement of another one of the needles.
In yet another aspect, the invention is directed to an actuator for an interventional surgical procedure comprising an actuator body having a distal end and a proximal end. An expandable section is located between the distal end and the proximal end. The expandable section is operable between a furled state and an unfurled state. The actuator includes means for causing the expandable section to change from the furled state to the unfurled state. A needle is located at the expandable section, and the needle is movable in an approximately perpendicular direction relative to a central longitudinal axis of the actuator body from a position within the actuator body to a position outside of the actuator body, when the expandable section is caused to change from the furled state to the unfurled state.
An implementation of the invention may include means for delivering a therapeutic or diagnostic agent to the needle.
An advantage of the invention is that it provides for highly-localized therapeutic or diagnostic agent deployments without significant risk to patients. The invention is able to generate a localized force that produces a microscale opening in the wall of an artery or vein without a significant axial motion component. This substantially eliminates the risk of tears to vessel walls. The invention produces a minute and self-healing wound. The invention permits, among other interventional procedures, localized tumor treatments and the treatment of in sclerotic arteries.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the invention will be apparent from the description and drawings, and from the claims.